<nav>
    <div class="navbar navbar-inverse">
        <div class="navbar-inner">
            <ul class="nav">
                <li><a href="index.php">Customers</a></li>
                <li class="divider-vertical"></li>
                <li><a>Inventory</a></li>
                <li class="divider-vertical"></li>
                <li><a>Orders</a></li>
                <li class="divider-vertical"></li>
                <li><a>Employees</a></li>
            </ul>
        </div>
    </div>
</nav>